1. Field of the Invention
The present invention relates to a digital broadcasting system, and more particularly, to an image display apparatus and operating method for images and data broadcasting contents in a digital broadcast receiving system.
2. Description of the Related Art
Generally, image formats used in digital broadcast are classified into standard definition (SD) having an aspect of 4:3 such as 720×480 p, and high definition (HD) having an aspect of 16:9 such as 1920×1080 i and 1280×720 p. Data broadcasting contents transmitted with images is stored suitable for the resolution of its image format. In this case, the data broadcasting contents of the resolution of 960×540 that has aspect of 16:9 are appended to image of the resolution of 1920×1080 i that is HD image format. The data broadcasting contents of the resolution of 720×480 (or 640×480) are appended to image of the resolution of 720×480 i that is SD image format.
The resolution and aspect of the data broadcasting contents are determined and made according to image format. And then they are transmitted with image and inputted as an input signal to the receiving system (image display apparatus). If all the broadcast contents are transmitted in HD and receiving system have uniformly fixed resolution and aspect no complex problems occur in displaying data broadcasting contents. However, there are actually HD and SD. Receiving systems (image display apparatuses) is required to support various output image formats in the range from an analog television format to an HD monitor. Even though the receiving systems (image display apparatuses) are HDTVs, they have two image display modes such as wide mode and standard mode that can be chosen by users. When the resolution of input image and data broadcasting contents is different from that of output image of image display apparatus, there are some problems to display the data broadcasting contents For example, if the output image of an image display apparatus is set to be SD (720×480) and an input image is HD (1920×1080i) and the display area of data broadcasting contents 960×540, data broadcasting contents area is not confined in the effective display area of image display apparatus as shown in FIG. 1. On the contrary, if the output image of the image display apparatus is set to be HD (1920×1080i) having aspect of 16:9 and an input image and contents area are SD (720×480), the input image does not fully occupy the screen of the image display apparatus and some area is remained. Besides many problems can be caused by the fact that the size and file resolution of the data broadcasting contents area are different from those of the output image area. It is because new broadcast means such as data broadcast that has not been use image display apparatus.